RTCSL started before GridPlay in 2017 by Venkellie as a fan group for residents who love trains
At one point in 2017 & 2018 before SLDA was founded, Ven and Sweetdebbie had a massive rail yard in the Taeniatum sim. The land was later sold in late 2018 so Ven and Deb could focus more on the new airport they created in Cavanaugh
The group itself is still going with rides made by IVE Tours every week.
GridPlay still monitors rail sims every hour and lists all sims on the rtcsl sub site.